The role of executive functioning in spontaneous confabulation.

OBJECTIVE

To follow the recovery course of a patient who exhibited an amnesic-confabulatory syndrome in conjunction with severe executive dysfunction in the first week following bithalamic infarction.

BACKGROUND

Previous studies have shown that spontaneous confabulation originates from the combination of amnesia and executive dysfunction and that the degree of confabulation is determined by the degree of executive dysfunction. However, a few studies have also reported a dissociation between spontaneous confabulation and executive dysfunction. Therefore, the role of executive functioning in spontaneous confabulation is presently unclear.

METHOD

Clinical examinations, magnetic resonance imaging (MRI), and cognitive and behavioral assessments with a focus on executive functions were conducted within the first week poststroke and after 6 months.

RESULTS

MRI showed a bithalamic infarction involving the territory of the paramedian arteries predominantly affecting the dorsomedial and intralaminar nuclei of the thalami. Disappearance of spontaneous confabulation paralleled a specific recovery in mental flexibility, whereas all other executive components and long-term memory remained severely impaired at 6 months poststroke.

CONCLUSIONS

Our case study provides additional evidence that mental flexibility, but not executive functioning in general, is a prerequisite for spontaneous confabulation. Direct or indirect functional deactivation of dorsolateral prefrontal cortex may be necessary for the development of spontaneous confabulation.